CVE-2019-2187 in Android
Summary
by MITRE
In nfc_ncif_decode_rf_params of nfc_ncif.cc, there is a possible out of bounds read due to an integer underflow. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-7.1.1 Android-7.1.2 Android-8.0 Android-8.1 Android-9 Android-10Android ID: A-124940143
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Analysis
by VulDB Data Team • 10/03/2020
The vulnerability identified as CVE-2019-2187 resides within the NFC (Near Field Communication) subsystem of Android operating systems, specifically in the nfc_ncif_decode_rf_params function located in the nfc_ncif.cc source file. This issue represents a critical security flaw that affects multiple Android versions including 7.1.1, 7.1.2, 8.0, 8.1, 9, and 10. The vulnerability manifests as a possible out of bounds read condition that stems from an integer underflow, creating a scenario where the system attempts to access memory locations beyond the intended buffer boundaries.
The technical nature of this flaw falls under CWE-129, which describes improper validation of array indices, and more specifically relates to CWE-191, integer underflow, which occurs when a calculation results in a value that is smaller than the minimum value that can be represented by the data type. The integer underflow in this context occurs during the processing of NFC radio frequency parameters, where the system fails to properly validate the size parameters before attempting memory operations. This vulnerability operates at the NFC controller interface level, which is responsible for managing communication between the NFC hardware and the Android framework, making it a core component of the device's wireless communication stack.
The operational impact of this vulnerability extends beyond simple memory access issues, as it can lead to local information disclosure. An attacker with local access to a vulnerable Android device can potentially extract sensitive information from memory locations that should remain protected. This information disclosure could include device-specific data, NFC communication logs, or other sensitive metadata that might be stored in adjacent memory regions. The lack of requirement for additional execution privileges means that any local user with basic system access can exploit this vulnerability, making it particularly concerning for devices where local security is not strictly enforced. The absence of user interaction requirements for exploitation further amplifies the risk, as the vulnerability can be triggered automatically during normal NFC operations.
The exploitation of this vulnerability aligns with ATT&CK technique T1059.001, which involves the use of command and scripting interpreter for execution, though in this case the exploitation occurs through memory manipulation rather than direct command execution. The vulnerability's presence in the NFC subsystem also connects to ATT&CK technique T1566, which covers the use of social engineering to gain initial access, as NFC-based attacks could potentially leverage this flaw to extract information from devices during normal NFC interactions. Organizations should implement immediate mitigations including applying the latest security patches from Google, which address the integer underflow by properly validating input parameters before memory operations. Additionally, system administrators should consider implementing network segmentation and access controls to limit local user privileges, while monitoring for unusual NFC activity patterns that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of input validation in low-level system components and highlights the need for comprehensive security testing of device drivers and hardware abstraction layers in mobile operating systems.